Media-feed assemblies

ABSTRACT

Media-feed mechanisms for business machines are provided. A media-feed mechanism comprises a frame, a stopper, a rotary member, and a swing gear mechanism. The rotary member comprises a cam contacting the stopper and a driven gear fixed to the cam. When the gear mechanism is in a first position, a first gear thereof engages the driven gear and rotates the cam in a first direction, to impel the stopper from a first angle to a second angle. When the swing gear mechanism is in a second position, a second gear thereof engages the driven gear and rotates the cam in the first direction, such that the stopper rotates from the second angle to the first angle.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates in general to media-feed assemblies and inparticular to media-feed assemblies preventing accidental feeding ofmultiple sheets.

2. Description of the Related Art

Referring to FIG. 1, a conventional media-feed assembly of a businessmachine primarily comprises a tray 12 with a sheet stack (not shown)disposed therein, a separator 14 on the bottom of the tray 12, a shaft16, a feed arm 18, and a feed roller 19 at an end of the feed arm 18. Asshown in FIG. 1, the feed arm 18 is pivotally connected to the shaft 16,and the shaft 16 is mounted to the side walls of the tray 12.

Generally, the sheet stack is pressed and fed by the feed roller 19,wherein the feed arm 18 is rotatable around the shaft 16 to adjust theangle thereof for feeding sheets of various thicknesses. When feeding,the lower sheets of the sheet stack are buckled by the separator 14, andonly the top sheet is fed. However, when the sheets are improperlydisposed in the tray 12 and exceed the separator 14, accidental feedingof multiple sheets may occur.

BRIEF SUMMARY OF THE INVENTION

Media-feed mechanisms for business machines are provided. A media-feedmechanism comprises a frame, a stopper, a rotary member, and a swinggear mechanism. The rotary member comprises a cam contacting the stopperand a driven gear fixed to the cam. When the gear mechanism is in afirst position, a first gear thereof engages the driven gear and drivesthe cam rotating in a first direction, to impel the stopper from a firstangle to a second angle. When the swing gear mechanism is in a secondposition, a second gear thereof engages the driven gear and drives thecam rotating in the first direction, such that the stopper rotates fromthe second angle to the first angle.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the subsequentdetailed description and examples with references made to theaccompanying drawings, wherein:

FIG. 1 is a perspective diagram of a conventional media-feed assembly;

FIG. 2 is a perspective diagram of an embodiment of a media-feedassembly;

FIG. 3 is a perspective diagram of an embodiment of a stopper;

FIG. 4 is a perspective diagram of a first gear engaged with a drivengear;

FIG. 5 is a perspective diagram of a first gear disengaged from a drivengear when meeting a toothless potion thereof;

FIG. 6 is a perspective diagram of a second gear engaged with a drivengear; and

FIG. 7 is a perspective diagram of a second gear disengaged from adriven gear when meeting a toothless potion thereof.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 2, a media-feed assembly of a business machineprimarily comprises a frame H, a stopper 51, a rotary member 61, and aswing gear mechanism 71. In this embodiment, the stopper 51, the rotarymember 61, and the swing gear mechanism 71 are pivotally connected tothe frame H. The frame H comprises a tray 41 with a sheet stack Sdisposed therein. The top sheet S1 of the sheet stack S is fed by aroller connected to the frame H, such as the feed roller 19 shown inFIG. 1, along a feeding direction A. The stopper 51 is rotatable withrespect to the frame H to selectively guide or block the sheets,preventing feeding of multiple sheets.

As shown in FIG. 3, the stopper 51 comprises a shaft 51 a pivotallyconnected to the frame H and a contact portion 51 b extending from theshaft 51 a, wherein the contact portion 51 b has a nub 51 c, such as anelastomer. Referring to FIG. 4, the rotary member 61 comprises a cam 61a and a driven gear 61 b fixed to the cam 61 a. In this embodiment, thecam 61 a and the driven gear 61 b are monolithically formed in onepiece, and the driven gear 61 b comprises an irregular toothless portion61 b′. Specifically, the driven gear 61 b and the cam 61 a are rotatablearound a central axis C thereof, and the nub 51 c maintains contact withan outer surface of the cam 61 a.

As shown in FIG. 4, the swing gear mechanism 71 comprises an arm 72, adriving gear 73, a first gear train 74, and a second gear train 75,wherein the driving gear 73 and first and second gear trains 74 and 75are rotatably connected to the arm 72. As shown in FIG. 4, the first andsecond gear trains 74 and 75 are engaged with the driving gear 73 fromopposite sides thereof, wherein the first gear train 74 has a first gear741, and the second gear train 75 has two second gears 751. In someembodiments, the first gear train 74 may have an odd number (such asthree or five) of first gears 741, and the second gear train 75 may havean even number (such as four or six) of second gears 751.

In FIG. 4, the contact portion 51 b and the sheets S form an includedangle α, and the sheets S are blocked by the contact portion 51 b fromfalling along direction A. When feeding the sheets S, the swing gearmechanism 71 rotates to a first position as shown in FIG. 4, such thatthe first gear 741 at the end of the first gear train 74 engages withthe driven gear 61 b of the rotary member 61. Subsequently, withclockwise rotation of the driving gear 73, the driven gear 61 b and thecam 61 a are rotated along a first direction A1 (clockwise), such thatthe contact portion 51 b descends from the angle α to the angle β (shownin FIG. 5), wherein β>α.

When the contact portion 51 b rotates to the angle β, as shown in FIG.5, the first gear 741 meets the toothless portion 61 b′ and disengagesfrom the driven gear 61 b, such that the contact portion 51 b is held inthe angle β. Hence, the top sheet S1 of the sheet stack S can be fed bythe feed roller.

After feeding, the swing gear mechanism 71 is reversely rotated with thedriving gear 73 (counterclockwise) from the first position to a secondposition, as shown in FIG. 6, such that a second gear 751 at the end ofthe second gear train 75 is engaged with the driven gear 61 b.Similarly, the cam 61 of the rotary member 61 is driven to rotate alongthe first direction A1 (clockwise) until the second gear 751 meets thetoothless portion 61 b′, as shown in FIG. 7, such that the contactportion 51 b is lifted to the angle α.

With rotation of the rotary member 61 along the first direction A1, thecontact portion 51 b returns from the angle β shown in FIG. 6 to theangle α shown in FIG. 7. Here, the swing gear mechanism 71 is disengagedfrom the driven gear 61 b when the second gear 751 meets the toothlessportion 61 b′, such that the contact portion 51 b can be held in angle βto block the sheets S from falling along the direction A.

To switch the media-feed assembly from the state shown in FIG. 7 to thestate shown in FIG. 5 for feeding, first, the swing gear mechanism 71 isreversely rotated with the driving gear 73 (clockwise) and returned fromthe second position to the first position shown in FIG. 4. Subsequently,the cam 61 a is driven by the first gear 741 to rotate along a firstdirection A1 (clockwise), such that the contact portion 51 b descendsfrom the angle α to the angle β, as shown in FIG. 5.

Media-feed assemblies are provided according to the embodiments. Whenthe swing gear mechanism 71 is in the first position, the driving gear73 rotates the cam 61 a along the first direction A1, such that thecontact portion 51 b of the stopper 51 descends from the angle α (shownin FIG. 4) to the angle β (shown in FIG. 5). Alternatively, when theswing gear mechanism 71 is in the second position, the driving gear 73rotates the cam 61 a along the first direction A1, such that the contactportion 51 b of the stopper 51 is lifted from the angle β (shown in FIG.6) to the angle α (shown in FIG. 7). Specifically, when the first gear741 or the second gear 751 meets the toothless portion 61 b′ of thedriven gear 61 b, the swing gear mechanism 71 is disengaged from thedriven gear 61 b, such that the contact portion 51 b can be selectivelyheld in the angle α or the angle β, to prevent accidental feeding ofmultiple sheets.

While the invention has been described by way of example and in terms ofpreferred embodiment, it is to be understood that the invention is notlimited thereto. To the contrary, it is intended to cover variousmodifications and similar arrangements (as would be apparent to thoseskilled in the art). Therefore, the scope of the appended claims shouldbe accorded the broadest interpretation so as to encompass all suchmodifications and similar arrangements.

1. A media-feed assembly of a business machine, comprising: a frame,comprising a tray with at least one media sheet disposed therein; astopper, pivotally connected to the frame and rotatable with respect tothe media sheet between a first angle and a second angle; a swing gearmechanism, pivotally connected to the frame, comprising a driving gear,a first gear train, and a second gear train, wherein the first andsecond gear trains are engaged with the driving gear; and a rotarymember, comprising a cam contacting the stopper and a driven gear fixedto the cam, the driven gear comprising an irregular toothless portion,wherein when the swing gear mechanism is in a first position, the firstgear train is engaged with the driven gear, to rotate the cam along afirst direction and impel the stopper from the first angle to the secondangle, and when the swing gear mechanism is in a second position, thesecond gear train is engaged with the driven gear, to rotate the camalong the first direction and return the stopper from the second angleto the second angle.
 2. The media-feed assembly as claimed in claim 1,wherein when the first gear train meets the toothless portion of thedriven gear, the swing gear mechanism is disengaged from the drivengear, and the stopper is held in the second angle.
 3. The media-feedassembly as claimed in claim 1, wherein when the second gear train meetsthe toothless portion of the driven gear, the swing gear mechanism isdisengaged from the driven gear, and the stopper is held in the firstangle.
 4. The media-feed assembly as claimed in claim 1, wherein thestopper comprises a shaft pivotally connected to the frame and a contactportion in contact with the cam.
 5. The media-feed assembly as claimedin claim 4, wherein the contact portion comprises a nub in contact withthe cam.
 6. The media-feed assembly as claimed in claim 5, wherein thenub is an elastomer.
 7. The media-feed assembly as claimed in claim 1,further comprising a feed roller connected to the frame, wherein themedia sheet is fed by the feed roller when the stopper is in the secondangle.
 8. The media-feed assembly as claimed in claim 7, wherein themedia sheet is blocked from feeding by the stopper when the stopper isin the first angle.
 9. The media-feed assembly as claimed in claim 7,wherein the second angle exceeds the first angle.
 10. The media-feedassembly as claimed in claim 1, wherein the first gear train comprisesan odd number of first gears, and the second gear train comprises aneven number of second gears.
 11. The media-feed assembly as claimed inclaim 1, wherein the swing gear mechanism further comprises an arm withthe first and second gear trains rotatably connected thereto.
 12. Themedia-feed assembly as claimed in claim 1, wherein the swing gearmechanism is moved between the first and second positions with thedriving gear.
 13. The media-feed assembly as claimed in claim 1, whereinthe driven gear and the cam are monolithically formed in one piece.